I Knew You Were Trouble
by PhinFerbIsMyLife
Summary: It's Phineas' time to choose between the two. Isabella. Emily. And he chooses Emily Kinney, Ferb's cousin. How would Isabella act in Phineas' debut? Find out! WARNING: Rated M for language and violence. You've been warned.


**Hey guys!**

**I'm back with a new story, and I hope you enjoy… This was rated M for foul language and violence…**

**I was inspired at watching the fan video of Taylor Swift's I Knew You Were Trouble by Isabella.**

**Characters:**

**Phineas-17 ½ **

**Isabella-18 **

**Ferb- 19**

**Emily-18**

**(To those who don't know Emily Grace Kinney, she was a Deviantart character made by someone. I don't know who made her. Just search it on .)**

**Disclaimer: I don't own the characters mentioned.**

* * *

Isabella was in her room, arranging her Supreme Fireside Girl Uniform. Her troop mates were still with her. Phineas was still in his backyard with Ferb, but they stopped inventing things. Instead, they're studying for their exam.

The Fireside Girl Leader gathered her troop mates for a conversation. She had the house for herself because her mother was running some errands. Gretchen, the co-leader, arrived just in time with Adyson, Katie, Milly, Holly, and Ginger.

Gretchen started the meeting, "Isabella, why did you gather us here?" Isabella grabbed the list, which was really not 'list'. "Hmm… Let's see. Can you guys help me to get Phineas the hint?" she asked with a slightly raspy voice. Adyson asked back, her arms crossed on her chest "Him again? Okay then. How may we help you?" Milly added, "Yeah. How are we going to help you with that?"

Silence passed on, and Isabella got a plan. "Ah! I've got an idea! Phineas' debut is tomorrow, right?" she stated. The girls agreed and nodded. "Let's distract him, and I can give him a passionate kiss! That's it!" Isabella explained. Gretchen thought that was not a really good idea. Ginger interrupted, "Uhm, excuse me, Isabella, but that was not really a great idea." "Stand down, Fireside Girl!" Adyson said, and she took hold of her sash. "I don't care! I have to see Phineas! Bye girls!" Isabella yelled and ran out of her house.

"Why did she left us?" they thought.

* * *

Phineas Flynn, a topnotcher on 4th year of high school, was on the Flynn-Fletcher backyard with his bachelor brother, Ferb Fletcher. They were studying about geography, when his classmate, Emily, showed up. Emily opened the door and greeted, "Hey Phineas! Hey Ferb! Whatcha doin?"

From Isabella's point of view, she sensed that someone was using her catchphrase.

And someone does.

Back to the residence, Phineas put his book down, and walked to his classmate. "Hi Emily. My brother and I were only studying our lessons. Hey! Can you help me how to get the solution for this?" he answered with such hesitation. Emily pulled Phineas closer to her. "Oh don't worry about that. I'll help you later." And she kissed Phineas.

Phineas started to froze, don't know what to do at this moment. Emily deepened the kiss and lowered her body. Although the boy was tasting her love from her lips, he held Emily's hand, absorbing every passion of his classmate.

* * *

Isabella arrived in the backyard, at the exact moment, at the exact time. She saw her boyfriend and her most hated enemy, kissing each other. Isabella felt her gut started to rise from her throat. Ferb approached to her and closed her eyes with his hands. "Isabella, that's bad." He said.

Isabella put away and took hold of Ferb's hand, and complained, "Ferb, I have to go." She ran to her house and sobbed. Ferb, on the front of the backyard's fence, looked worriedly as Isabella ran to her very own home.

* * *

Phineas and Emily pulled out each other, panting. He can't believe he kissed someone. But not Isabella. Emily. Emily. Emily. He thought about her a thousand times. Emily said to his classmate, "Phineas, that was great. I've never felt like this before. I felt like I was in heaven already." "Yeah. Yeah it was." He took hold of Emily's hand and explained, "Emily, I've been thinking lately, that I may have some feelings for you. I'm going to say it. I. Love. You. Emily. Kinney." He muttered. Emily was shocked at Phineas' explanation.

Ferb heard of what Phineas and his cousin were talking about. 'He loved her?' he thought. Phineas knows that it's wrong to love his cousin to be his girlfriend, since she was Ferb's relative. The British teen walked his way to the kitchen. He had spit out the snack he had eaten, since his brother and cousin were kissing.

"Isabella, what's wrong?" The Fireside Girls asked her and asked until she answers. Gretchen gave her some tissues to wipe her tears away. "Come on Isabella. You can tell us. We're your best friends." The girl in spectacles looked for answers to why she is crying.

Isabella answered, trying to get those words out of her mouth. "P-P-Phineas. He kissed—he— HE KISSED FERB'S COUSIN! HOW WILL I NOT CRY ABOUT THAT HUH?!" "Calm down Isa. We know you're heartbroken. But I got a tingling plaaaaan!" Ginger apologized and raised her finger up.

The rest of them looked awkwardly at the Japanese teen. "Isabella said earlier that Phineas' debut was tomorrow, so she had to attend. And when a karaoke is played, she will first pick a complement song of her choice, sing it in front of people, and after, slap him! Agree, girls?" Ginger explained continuously which no one can understand. Probably, they've understood of the plan.

"Very Agree!" the troop yelled. Isabella stopped sobbing and hugged Ginger. "Thanks Ginger for the plan." She thanked her.

* * *

-Later that night at Phineas' house-

Linda and Candace were preparing their dinner for tonight. Phineas, Ferb and their dad were already sitting on their assigned dining chairs, waiting for the two women. "So Phineas, your mom and I have been thinking, since tomorrow is your debut, you can invite your friends, and your girlfriend, Isabella." Lawrence asked his step-son. Phineas thought about Isabella, and he felt sorry about her. "Dad, Isabella's only my friend." He said.

Isabella sensed it again. Ouch.

Ferb, Linda and Candace are both opened-mouths of Phineas' statement, followed by a big "What?" Candace walked to her brother and asked, "Is that true, Phineas?" "Yes, Candace. She's only my best friend. And that's it." The redhead complained and continued reading his book.

"By the way, Mom, can I really go invite my friends? Tomorrow?" Phineas questioned. "Sure. It'll be fun." Her mother responded back.

"Bye Mom! Bye Dad! Bye Candace! Bye bro!" was the reply the rest of Phineas' family got.

Phineas arrived at Isabella's house to invite her for a dance at his debut tomorrow. He knocks at her house's door.

Adyson has been aware that it was really Phineas. "This is it, Isabella. Whatever it is, you will accept it, then the plan is going to be a success." "Adyson, Adyson, Adyson. I know what I'm doing."

Isabella opened the door, and felt the anger strike her again. "Phineas! What do you want from me?!" She yelled. "Uhm Isabella, I just want to invite you for my debut party tomorrow. It'll be fun, I promise!" Phineas continued, as if he were dying the next day without his best friend.

"You want me to go with you? Tomorrow?" Isabella asked back.

"Yeah! It'll be sooooooooo much fun!"

"Oh…Kay? Bye!" She said, and slammed the door shut. Isabella went back to where she was, earlier.

"He wants us to go." "Really?" the fellow members questioned, with their awkward looks. "Ya."

* * *

-At Phineas' Debut-

"Gretchen? Are you ready yet?" the leader Isabella asked. The other friends of her were having a discussion before going to the debut. "This is it, gals! We've got the big chance to get the plan going. So, Supreme Fireside Girls, Assemble!" Isabella yelled, then they put together as one team that could not give up each other.

They said back, "To Phineas' Debut!"

* * *

-One Hour Later-

"Alright, fellas! Who's up for a karaoke?" Phineas called all the visitors at his party, and he got their attention.

"Ooooh! Ooooh! Me, Phineas! Mee!" Isabella shouted over joy, and excitement. 'Me! I want to slap you on the face!' she thought to herself, and glanced to her long-time crush. Now that she'd knew the plan, she'd like to get it goin'.

"Okay, Isabella! You're the first one to sing!" the triangle-headed teen said.

Isabella had chosen a song, and the title is 'I Knew You Were Trouble' by Taylor Swift.

She started to speak, "Hey everyone! This song is for someone who owes me a slap, Phineas Flynn!" The said boy let out a groan.

Isabella sang:

Once upon a time a few mistakes ago  
I was in your sights, you got me alone  
You found me, you found me, you found me  
I guess you didn't care, and I guess I liked that  
And when I fell hard you took a step back  
Without me, without me, without me

And he's long gone when he's next to me  
And I realize the blame is on me

'Cause I knew you were trouble when you walked in  
So shame on me now  
Flew me to places I'd never been  
'Til you put me down, oh  
I knew you were trouble when you walked in  
So shame on me now  
Flew me to places I'd never been  
Now I'm lying on the cold hard ground  
Oh, oh, trouble, trouble, trouble  
Oh, oh, trouble, trouble, trouble

No apologies. He'll never see you cry,  
Pretend he doesn't know that he's the reason why.  
You're drowning, you're drowning, you're drowning.  
Now I heard you moved on from whispers on the street  
A new notch in your belt is all I'll ever be  
And now I see, now I see, now I see

He was long gone when he met me  
And I realize the joke is on me, yeah!

I knew you were trouble when you walked in  
So shame on me now  
Flew me to places I'd never been  
'Til you put me down, oh  
I knew you were trouble when you walked in  
So shame on me now  
Flew me to places I'd never been  
Now I'm lying on the cold hard ground  
Oh, oh, trouble, trouble, trouble  
Oh, oh, trouble, trouble, trouble

And the saddest fear comes creeping in  
That you never loved me or her, or anyone, or anything, yeah

I knew you were trouble when you walked in  
So shame on me now  
Flew me to places I'd never been  
'Til you put me down, oh  
I knew you were trouble when you walked in (you were right there, you were right there)  
So shame on me now  
Flew me to places I'd never been  
Now I'm lying on the cold hard ground  
Oh, oh, trouble, trouble, trouble  
Oh, oh, trouble, trouble, trouble

I knew you were trouble when you walked in  
Trouble, trouble, trouble  
I knew you were trouble when you walked in  
Trouble, trouble, trouble.

* * *

"Everyone, clap your hands for Isabella Garcia-Shapiro!" Phineas announced. He's nervous that she will slap him any minute.

"Phineas? Phineas?! PHINEAS?! Come over here. I've got something for ya." Isabella called over. She's ready to do the plan. Her hands are ready. Her body is ready. And Phineas doesn't know.

She scooped Phineas' jaw as the teen boy walked closer. "Phineas, this is my gift for you." SLAP! "Ouch! Isabella! That hurts!" Phineas crooned.

The audience murmured to their friends, "Whoa." "What did she do?" Why did she slap him?" The atmosphere was filled with murmurs and questions.

"THAT is for lying to me!" She yelled. SLAP! "THAT is for cheating to me!" Isabella yelled again.

"Isabella! Stop! You know it hurts!" Phineas pleased. "NO, PHINEAS! I'M NOT FINISHED YET!" SLAP! "And THAT is for kissing Emily!"

"Wait? H-How did you know?" Phineas asked while cupping his cheeks, due to pain.

"Oh! I know because of Ferb!" Isabella shouted, while pointing her finger at Phineas' eyes. "I'M OUTTA HERE! C'MON GIRLS!" She violently said, leaving Phineas crying in extreme pain.

The former Fireside Girls followed Isabella on her way to her home.

* * *

-That Night-

"Ferb, I-I don't understand. I mean why she is mad at me?" Phineas asked.

No answer.

"Ferb." He called.

Still, no response.

"FERB! WHY CAN'T YOU JUST FUCKING ANSWER?! I'M ASKING YOU!" Phineas yelled.

Finally, Ferb answered in a shouting voice. "IT'S BECAUSE YOU KISSED MY COUSIN! YOU HURT ISABELLA'S FEELINGS! I FUCKING HATE YOU, PHINEAS!"

* * *

**Was this great? I mean this is my first story that Isabella made such strong violence. And Phineas and Ferb, too. I knew that. By the way, R&amp;R guys!**


End file.
